I keep getting in spots on the river where I am using nut flush blocker or nut straight blockers and putting them into my over bet river range and balancing that with my actual nutted hands. However, I keep getting jammed on and it is just not making sense to me. How often are lower flushes actually jamming here?

For example hand last night
I open Ad9c cutoff. SB defends.
Flop Jd 8s Ts
I cbet like 60%, SB calls.
Turn Jd 8d Ts 6s
check x2
River (14bb) Jd 8d Ts 6s 2d
Hero bets 25bb
SB check raises all in 98bb

What is happening? Should I just stop bluffing with these nut blockers? I don't mind getting called, just don't understand how they jam over it without nutted hand. Are non nut hands supposed to jam?